If that custom content is protected you cannot edit it but if you're not using all of your premium add-ons you can contact those premium makers you don't want anymore and ask them to disable that content so it prevents those custom columns from loading in your PokerTracker 4. Alternatively you can remove the check mark from the PokerTracker 4 option "Configure -> Options -> Download Premium Content" then close/restart PokerTracker4 but this will disable all premium content. If you want to see how many custom columns you are using click your Windows Start button then type the following:
pgadmin
and click on it when it appears. Double click on "PostgreSQL x.y" (where x.y is your PostgreSQL version) and if your prompted for a password the default is "dbpass" (without the quotes). Next double click on "Databases -> YOUR_DATABASE_NAME -> Schemas -> Public -> Tables -> cash_custom_cache (and/or tourney custom cache for tournaments) and the number in brackets is the number of custom columns which should look
like this. Before making any of these changes or accessing PGAdmin I'd recommend backing up your PokerTracker 4 customisations and poker data first - see
this guide.